Simon had the show nailed from the beginning. Near the end of the overview, he says:

But more than an exercise is realism for its own sake, the verisimilitude of The Wire exists to serve something larger. In the first story-arc, the episodes begin what would seem to be the straight-forward, albeit protracted, pursuit of a violent drug crew that controls a high-rise housing project. But within a brief span of time, the officers who undertake the pursuit are forced to acknowledge truths about their department, their role, the drug war and the city as a whole. In the end, the cost to all sides begins to suggest not so much the dogged police pursuit of the bad guys, but rather a Greek tragedy. At the end of thirteen episodes, the reward for the viewer — who has been lured all this way by a well-constructed police show — is not the simple gratification of hearing handcuffs click. Instead, the conclusion is something that Euripides or O’Neill might recognize: an America, at every level at war with itself.

The list of main characters contains a few surprises. McNulty was originally going to be named McCardle, Aaron Barksdale became Avon Barksdale, and the Stringer Bell character changed quite a bit.

STRINGY BELL - black, early forties, he is BARKSDALE’s most trusted lieutenant, supervising virtually every aspect of the organization. He is older than BARKSDALE, and much more direct in his way, but nonetheless he is the No. 2. He has BARKSDALE’s brutal sense of the world but not his polish. BELL is bright, but clearly a child of the projects he now controls.

The final section is entitled “BIBLE” and contains draft outlines of a nine-episode season. I didn’t read it all, but the main story line is there, as are many plot details that made it into the actual first season. (thx, greg)